Electric circuit interrupter or breaker



July 21, 1942. o. G. GRIESBACH ELECTRIC CIRCUIT INTERRUPTEH 0R BREAKER Filed April 1, 1940 2 Sheets-Sheet 1 fry/971 57": 0,12 5 6' 72:29 85M July 21, 1942. o. s. GRIESBACH ELECTRIC CIRCUIT INTERHUPTER 0R BREAKER Filed April 1, 1940 2 Sheets-Sheet 2 5N xi f 87%;? 0w6ra'esacfa 5% W ZW Patented July 21, 1942 UNITED STATES PATENT OFFICE ELECTRIC CIRCUIT DITEBRUPTER R BREAKER Otto G. Grieabaoh, Chicago, 111., winter to Barbara Moore Eight, Chicago. Ill.

Application April 1, 1940, Serial No. 327,128

12 Claims.

This invention relates generally to new and useful improvements in electrical circuit inter-' on a single base plate pivotally mounted upon the breaker supporting plate within the breaker casing.

Another object or my invention is found in the provision of a cam-engaging nber block operatively associated with one ofthe breakerpoint supporting arms and wedge means on the base plate cooperating with a spring-pressed member for automatically adjusting the camengaging block relatively to the rotary cam to compensate for wear of such block -caused by its repeated contacts with the rotating cam. The automatic adjustment of such cam-engaging fiber block permits assembly of the breaker unit and pre-setting of the breaker points at the factory, and eliminates the usual necessary adjustment of the breaker points by mechanic during installation since the breaker points and their resilient supporting arms are properly set and assembled with the supporting base plate at the factory and therefore such assembled unit may be readily mounted upon the breaker supporting plate and automatically set in operative position by the spring-pressed member without further adjustment of the breaker points.

Another object of'my invention resides in the provision of a single base plate for supporting a pair of movable, and preferably relatively movable, fiexible breaker-point supporting arms, a single cam-engaging block carried by one of the breaker-point supporting arms, and springpressed means for retaining the base plate in practically stationary position while said breaker points are repeatedly moved into make and break positions by the rotating cam.

While the base plate is non-oscillatable at each make and break it is. however, adapted i'or slight automatic adjustment movement respon siveiy to the wear of the cam-engaging block and the action 01 the spring-pressed wedge means to thereby compensate for such wear and thus maintain proper timing of the make and break action of the breaker points.

Still another feature of my invention is found in the provision oi'flexible lightweight-breakerpivoted non-flexible base plate and additional pressure-balancing springs for the breaker point flexible supporting arms whereby a true flat face to face contact of the breaker points is assured,'

and the adaptability of such lightweight breaker to high speed operation is made possible by the elimination of objectionable chatter or bounce and the resulting irregular timing and decreased dwell which hinder the proper electrical build-up of the coil.

A further object of my invention resides in the provision of a circuit breaker having a pair of comparatively light-weight flexible breaker-point supporting arms mounted on a common base plate and each of such flexible arms provided with a coil spring resisting flexing of such arms whereby not only uncontrolled oscillations of such light-weight arms are prevented but more per-' point supporting arms mounted on a common iectly balanced spring pressures are attained through springs of comparatively small tension.

A still further object oi my invention is found in the novel construction and arrangement of the cam-engaging block which is provided with a laterally disposed slot or recess constituting a pocket for a grease lubricant. A fiber retainer may be provided at one end of the block to insure retaimnent oi the grease therein, or the retainer may be provided within the block recess.

A still further object of my invention is to provide a timer wherein, due to the simplified construction and mounting of the breaker-pointing supporting arms on a common base plate and the elimination of bushings for the arms, the unit is rendered susceptible to precision manufacture and assembly eliminating play and providing an accurately centered full-face contact of the faces of the points under very small tolerances.

Still another object of my invention is found in-the assembly and mounting of the breakerpoint carrying arms on a common pivotally mounted base plate, the pivotal center of which is different from that of the arm supporting the cam-engaging block whereby cam angle can be more accurately maintained with a wide camengaging block.

With the above and other objects in view, which will become apparent from perusal of the toliowing specifications and attached drawings, my invention consists in the novel combination, construction and arrangement of the parts and members shown in preferred embodiment in the attached drawings, described in the following speciiications and particularly pointed out in the appended claims.

sure of coil spring ll to thereby cause successive engagement of the point 43 of the arm ll with the point 48 of the breaker arm 8| whereby the circuit will be repeatedly closed and opened during the rotation of the, cam it.

The flexing movement of the arm a is such that, in the closing of the circuit through the engaged points It, the arm it will also be flexed against the pressure of its coil spring 40 and duringsu iiexingof thearmsltand II the breaker po ts 48 will, during their engagement with one another, he moved slightly relatively one to the other to cause a wiping contact therebetween due to the difference in the lengths of the arms II and it.

From the above description and attached drawings it will be readily apparent that I have provided an electric circuit breaker or interrupter which includes the following novel features:

Two flexible breaker-point carrying arms mounted on a common pivoted supporting base plate which base plate is automatically adjustable relatively to the operating cam responsively to the wear of the cam-engaging block mounted on one of the breaker-arms.

One of the breaker-point carrying arms is preferablylonger than the other one of the breaker arms, and one of the breaker arms is preferably slightly angularly disposed relatively to the other arm to thereby cause a slight wiping movement between. the breaker arm points during their circuit closing and opening operations.

The breaker arms are made of a comparatively light-weight flexible metal, both of the breaker arms are slightly flexed during their movement by the cam into closed circuit position, and each of the breaker arms is provided with an auxiliary coil spring at or near its unsecured end to insure smooth operation under high speed cam operation by the elimination through such balanced resiliency of undesirable irregular oscillations of the breaker arms.

In the modified construction of my invention. as illustrated in Figs. 8, 9 and 10, the parts and members which are similar to or like those abovedescribed, and shown in Figs. 1 to 'l inclusive, are indicated by like reference numerals and therefore, a description of these similar or like parts is omitted.

The modified parts and novel features embodied in Figs. 8. 9 and 10, include the following:

The shorter resilient breaker arm 51, which is supported on the upstanding support 23, is arranged to be normally positioned with its free end supported upon the narrow pin-like projection is which is formed integrally with the angularly bent strip 58 of soft metal such as, for example, soft brass. The assembly and arrangement is such that this pin-like projection 58 of soft metal of somewhat preferably pointed formation will, in a new breaker arm assembly, support said arm ii and its breaker point it in proper spaced positiaon relatively to the arm 26 and its breaker point 4 1 Being oi comparatively soft metal. this narrow pointed projection 58 is subjected to repeated engagement by thevibrating end of the arm 61 and is gradually flattened at its pointed end to there= by permit the free end of the arm ll to progressively assume a normal position closer to the arm It due to the pressure of spring ll which tends -to normally maintain the arm I'I seated onthe projection 58.

The function of such permissible wear of the projection is is to provide means for compensating the usual amount of wear of the new points 0. 1n the modification shown in Figs. ii. 9 and 10, the spring II is retained in position between the arm I! and the upstanding base plate retaining wall It in axial alignment with the points 48. The wall It is formed integrally with the base plate it, and is disposed angularly relatively to the base plate integral supports 22. It and to constitute an engagement wall for the automatically adjustable wedge member it.

The spring It is held against displacement by the engagement of one of its ends about the headed portion ll of the point 48 and by the engagement of its opposite end about the stud I: pressed out of the wall 60. This construction eliminates the rivet ll shown in Figs. 2: 8 and 5.

as shown in Fig. 8, the cam-engagement block 48 is preferably provided with an arcuate grease retainer OI consisting -01 arouate strip of electri-= cally non-conductive pressed flber secured within the slot 41 by the block retaining rivet 64. This arcuate retainer 83 will resist displacement of a fibrous grease composition from the slot 41.

I claim:

i. In an electric circuit breaker. the combination with a rotatable cam, of electric circuit interrupting means adapted for actuation by said cam comprising a single movably mounted support, a pair of flexible arms mounted on said support and operatively interposed in an electric circuit, a contact on each of said arms. auxiliary resilient means resisting the flexing of said arms in one direction. said cam being adapted to intermittently flex one of said arms to thereby intermittently move its said contact into contact with the said contact on the other of said arms against the pressure of said resilient means to thereby intermittently close and open the circuit, said support being held instationary position during the flexing of said one of said arms by said cam, and spring-pressed means for automatically moving and retaining said support in proper adjusted position relatively to said cam.

2. In an automobile ignition circuit interrupter, a. rotatable cam, a pair of flexible breaker arms, a contact point carried by each of said arms, said arms being adapted to be intermittently flexed by said cam to intermittently close and open the ignition circuit through said contact points, and a stop for limiting the movement of one of said breaker arms in one direction. said stop being of a comparatively soft material adapted to be progressively flattened by successive impacts of said one of said breaker arms to thereby compensate for the wear of said contact points whereby said contact points will be retained in substantially proper relatively spaced open-circuit posit on.

3. In an automobile ignition circuit breaker adapted to be actuated by a rotatable cam to intermittently close a normally open ignition circuit, a movable support mounted adjacent said cam, a pair of arms mounted on said movable support and operatively interposed within said ignition circuit, a circuit-closing contact carried by each of said arms, said contacts being. in open-circuit position, slightly axially dlsaligned and one of said arms being movable by said cam independently of the movement of said support to move its circuit-closing contact into intermittent wiping contact with the circuit-closing contact on the other of said arms. and spring-pressed means urging said movable support toward-said cam and preventing opposite movement of said movable support away from said cam whereby one of said matically moving and retaining said support in proper adjusted position relatively to said cam.

4. In an automobile ignition circuit interrupter adapted to be actuated by a rotatable cam to intermittently close a normally open ignition circuit, a movable support mounted adjacent said cam, a pair oi arms movably mounted on said support and operatively interposed within said ignition circuit, a circuit-closing contact point carried by each oi said arms, said arms being mov able independently oi the movement 01. the support and independently oi one another, a camengageable member carried by one of said arms, said member being movable by said cam to thereby oscillate its supporting arm and contact point thereon to cause its contact point to be brought into successive contacts with the contact point on the other said arms whereby the ignition circuit will be intermittently closed, and automatically adjustable spring-pressed means urging said movable support with said cam-engageable member into constant contact with said cam and preventing opposite movement of said movable support whereby said cam-engageable member is positively retained in constant contact with the cam during the oscillation oi its supporting arm.

5. In an automobile ignition circuit breaker as embodied in claim 4 and wherein said support is pivotally mounted and wherein said pair oi arms each consists oi a flexible member rigidly connected at one end to said pivotally mounted support.

B. In an automobile ignition circuit interrupter as embodied in claim 4 and including each oi said arms consisting oi a flexible member rigidly secured at one end to said movable support. End auxiliary resilient means resisting the flexing oi said arms in one direction.

7.- In an automobile ignition circuit interrupter adapted to be actuated by a rotatable cam to intermittently close a normally open ignition circuit, a support pivotally mounted adjacent said cam, a pair oi resilient arms each rigidly secured at one end thereof to said support, said arms being operatively interposed within said ignition circuit, a contact point carried by each of said arms, a. pair of spaced supports on said pivoted support, 'a coil spring carried on each oi said spaced supports, said coil springs resisting the movement oi said resilient arms in one direction, a block carried by one oi said resilient arms in constant engagement with said cam and said block-carrying arm being oscillatable by the engagement of said cam with said block whereby the contact point on said block-carrying arm is brought into intermittent contact with the contact point on the other oi said resilient arms against the pressure oi said coil springs, and spring-pressed means urging said pivoted support toward said cam whereby said block is constantly retained in operative contact with said cam.

8. In an automobile ignition circuit interrupter as embodied in claim 'i and including an upstanding wall iormed integrally with said pivoted sun port, and said spring-pressed means comprising a spring-pressed wedge in constant contact with said wall whereby said pivoted support is urged toward said cam to thereby retain said block in constant contact with said cam.

9. In an automobile ignition circuit interrupter as embodied in claim 4 and including a stop lor limiting the movement oi one 0! said arms in one direction, said stop being 01 a comparatively soit material adapted to be progressively flattened by successive impacts oi said one oi said arms to thereby compensate tor the wear oi said contact points whereby said contact points will be retained in substantially proper relatively spaced open-circuit position.

10. In an electric circuit breaker as embodied in claim 'I and including said circuit-closing contacts substantially axially aligned, a coil spring resisting the movement oi said block-supporting arm in one direction, said other arm having a coil spring axially aligned with its circuit-closing contact resisting its movement in one direction.

11. In an electric circuit interrupter adapted to be actuated by a rotatable cam to intermittently close a normally open circuit. a support pivotall mounted adjacent said cam, a pair oi movable arms each supported at one end upon said pivotally mounted support, said arms being operatively interposed within the electric circuit, a circuit closing contact carried by each oi said arms, said arms being movable independently oi the movement oi said support, a cam-engageable member carried by one oi said arms, said cam-engageable member being intermittently movable by said cam to thereby intermittently move its supporting arm and circuit closing contact thereon to cause such contact to be brought into successive circuit-closing engagements with the contact on the other oi said arms, and springpressed means urging said pivotally mounted support with said cam-engageable member into constant contact with said cam, said arm, which supports said cam-engageable member, being movable about a center of movement at its support which is non-coincident with the center oi the pivotal movement of said pivotally mounted support whereby said cam-engageable member is adapted to move simultaneously in two non-coincident arcs.

12. In an electric circuit breaker, the combination with a rotatable cam, of electric circuit interrupting means adapted for actuation by said cam comprising a single pivotally mounted support, a pair oi flexible arms mounted on said support and operatively interposed in an electric circuit, circuit closing contacts, one on each oi said arms, a cam-engageable block flxedon one oi said arms, said cam having constant engagement with said block during its rotation whereby said block-supporting arm is intermittently flexed to thereby intermittently move its contact into closed circuit contact with the said contact on the other of said arms, and spring-pressed means ior automatically maintaining said pivoted support in operative position wherein said block is positively maintained in constant engagement with said rotatable cam, said pivoted support being automatically movable about its pivot toward said cam responsively to the amount oi wear oi said block, said spring-pressed means comprising a spring-pressed slidably mounted wedge member in contact with said pivoted support urging said pivoted support toward said cam.

OTTO G. GRIESBACH. 

